Sewing-machine slack-thread controller.



PATENTED MAY 21, 1907. 2

W. HJSTBDIMAN. SEWING MACHINE SLACK THREAD-CONTROLLER.

APPLIOATION FILED MAR. 19, 1504.

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UNITED STATES WILLIAM H. STEDMAN, OF HARTFORD PATENT OFFICE.

, CONNECTICUT, ASSIGNOR TO THE RATION OF CONNECTICUT.

SEWING-MACHINE SLACK-THREAD CONTROLLER- Specification of Letters Patent.

Patented May 21, 1907.

Application filed March 19,1904. Serial No. 198,965.

To all whom it may concern;

Be it known that LWiLLiAM H. STEDMAN, a citizen of the United States, residing in the city of Hartford, State of Connecticut, have invented certain new and useful Improvements in Sewing-Machine Slack-Thread Co ntrollers; and I do hereby declare the following to be a full, clear, and exact description of the same, reference being had to the accompanying drawings, forming a part of this specification, and to the figures and letters of reference marked thereon.

This invention relates to improvements in slack thread controllers its object being to provide mechanism of improved construction which will facilitate adjustment and control of the controller spring, as well as support and protect the same.

The invention is particularly applicable to sewing machines and the controller is preferably, though not necessarily, combined with a tension device. It is shown and described herein as combined with a well known form of tension device. I

In the accompanyingdrawingsFigure 1 is an elevation showing a controller and also a portion of an overseaming machine, the lat ter being partially in dotted lines. Fig. 2 is a plan with parts in section, the section-being taken on the line 2*2 of Fig. 1. Fig. 3 is a view showing the controller mechanism on a somewhat enlarged scale and partly in hori- Zontal section. Fig. 4 is a view showing the controller spring in position in its inclosing case, the supporting pin or rod being in section. Fig. 5 is a plan View of the side of the supporting rod opposite to that shown in the Fig. 3, and illustrates particularly the means wheieby the controller spring is secured thereto. Fig. 6 is a detached perspective view of the controller spring.

Like letters of reference indicate the same parts in all the figures.

The controller mechanism when acting upon the needle thread of a sewing machine is usually secured to a fixed portion of the machine itself and preferably as shown in the drawings, in a location suitable for the thread to render to the needle a, the latter being mounted in a carrier b the oscillations of which carry the needle point alternately above and below the needle plate 0.

Referring now particularly to the controller itself, the letter (1 denotes a rod on which various elements constituting the device are mounted, the said rod in this instance serving also as the rod of the tension device. The letter 6 indicates a circular box forming a spring case, and provided on its rear face with a tubular hub or sleeve 0 within which the rod (2 is adjustably secured. The machine frame is bored to receive the hub e of the spring case 6 and is also drilled and tapped for a set screw f having a rounded end adapted to pass through a hole 6 in the hub e and enter an annular groove d near the end of the rod (1.. When in this position the set screw f prevents longitudinal and lateral movement of both the case and the rod but, upon being eased back slightly, the said rod may be rotated (as hereinafter explained) within the hub of the spring case but will be held against appreciable longitudinal movement.

The controller spring g is preferably helical having several coils, the same being wound substantially'like a watch spring but being constructed of round wire. It is mounted upon and secured to the rod d within the case a and the inner coil or coils of the spring are of proper internal diameter to fit the rod d or more properly an enlargement d of the said rod. At the inner end of the coil, the wire is bent to form a short projecting end g extending approximately at right angles to the plane of the springs coils and to the plane in which the free end of the spring vibrates and the enlarged portion d of the rod is grooved parallel with its axial line as at d to receive said projection g and prevent the rotation of the spring on the rod, the said spring being further held in position by the spring case cover as will be more fully explained.

Near its outer end, the wire of which the spring is formed, is bent outwardly or away from the center of the spring, as at 9 the portion g extending through an opening 6 in the peripheral wall of the spring case and having a hook 9! at its end through which the thread renders.

The spring case is closed and the spring re tained in position therein by a cover 7c having a central opening for the rod enlargement d When the cover is is in place the portion 9 of spring case 6.

the controller spring passes through the central opening of the said cover and is thus held in the groove 61 of the rod (1.

As already stated, the rod (1 may also form the central rod or pin of the tension device, the disks mm of which are located on the rod enlargement d adjacent the spring case cover 76 and the outer end of the rod (1 is threaded to receive the tension nuts nn between which and the tension disks the tension spring 0 is confined and serves not only to hold the tension disks in frictional engagement with each other, but also holds the disks against the spring case cover 7c and retains the latter in position.

The thread 8 is shown as rendering through an eye 15 thence between the tension disks mm, thence preferably though not necessarily, to and around a pin u intermediate the tension disks and the spring hook g thence to the said hook of the controller spring and finally to the needle a. In the downward travel of the needle, the thread as it renders forward, draws the end of the spring downward as shown in dotted lines in the Fig. 1, but in its upward travel the spring end 9 also travels upward as it seeks to regain its normal position thereby keeping the thread taut. The upper shoulder e of the opening a in the spring case 6 forms a stop to limit the upward travel of the end of the spring. In the Fig. 4 the said spring end g is shown in full lines as drawn downwardly by the thread away from the said stop and in dotted lines as having returned into engagement therewith. The tension of the controller spring may be increased or diminished by winding or unwinding the same to cause it to bear with a greater or less degree of force against the said stop a this being accomplished by rotating the rod d within the rotated by grasping the tension nuts nn which act as check nuts upon each other and move in unison with the rod. In effecting this adjustment the set screw f is first eased back sufliciently to allow rotation of the rod and after the adjustment is made'the set The rod may be conveniently screw must be tightened to hold the rod cl from rotating.

The spring 9 may if desired be so adjusted relatively to the case 6 that its normal position shall be approximately that shown in full lines in Fig. 4 and when so adjusted the amount of controller movement possible for the spring end 9 is less than when the spring is adjusted as first described.

Having thus described my invention what I claim as new and desire to secure by Letters Patent, is:

1. In a sewing machine slack thread con troller, the combination with an angularly adjustable rod and a controller spring having one end connected with the rod, of a casing inclosing the spring, a screw engaging the easing to retain it in position and also engaging the rod to hold it in its position of angular adjustment and a fixed support for the screw, rod and casing; substantially as described.

2. In a sewing machine slack thread controller, the combination with the frame an angularly adjustable rod, a casing having a bearing in which said rod is journaled and itself supported in the frame and a set screw passing through said bearing and engaging the rod to hold it in its position of angular adjustment, of a controller spring located within the casing and having its inner end connected with the rod; substantially'as described.

3. In a sewing machine slack thread controller the combination with the frame the angularly adjustable rod, the casing having a central bearing for the rod and supported in the frame and the set screw passing through said bearing and engaging the rod, of the controller spring having its inner end connected with the rod and its outer end passing through the wall of the casing, the tension disks on the rod and closing the outer side of the casing, the spring around the rod outside of the disks and the adjusting nut on the end of the rod; substantially as described.

WILLIAM H. STEDIWIAN.

Witnesses:

W. A. W. STEWART, ALONZO M. LUTHER. 

